1. Field of the Invention
The invention relates to a cutting apparatus, more particularly to a cutting apparatus for use in a machine tool.
2. Description of the Related Art
In machining a polygonal rod, i.e., a rod with a polygonal cross-section, a workpiece is first turned by a lathe to form into a circular rod, and then machined by a polygonal turning machine to form the polygonal rod.
During the turning operation of the lathe, the workpiece is first held and rotated by a chuck. Then a lathe tool is operated to advance in both radial and axial directions of the workpiece to cut the workpiece, such that a circular rod that has a desired diameter and a desired length is formed at the machined portion of the workpiece.
In the forming process of the polygonal rod, the workpiece is held and rotated by a chuck of the polygonal turning machine. Then a polygonal cutter that rotates in a rotational direction the same as that of the workpiece is operated to cut the workpiece into the polygonal rod.
However, the removal of the workpiece from the lathe and the loading of the same on the polygonal turning machine are time-consuming and may affect the machining precision.
Another conventional machine tool is equipped with a lathe tool and a separate polygonal cutter to respectively perform turning and polygonal turning operations. However, in the machining process of the polygonal rod, the lathe tool and polygonal cutter need to be positioned relative to the workpiece in turn. As a result, the machining precision may still be affected.